Driving device for rotary chemical machine

ABSTRACT

A driving device for a rotary chemical machine such as a centrifugal separator having a reduction gear mechanism contained in a rotary casing, a torque control mechanism for imparting a desired torque to the output shaft thereof and including a braking element responsive to control means for measuring the load demand in the motor by the centrifugal separator. Thus, the device provides variable torque responsive to the load at the output shaft.

United States Patent Tadokoro 111' 3,851,819 [451 .Dec. 3, 1974 41DRIVING DEVICE FOR ROTARY CHEMICAL MACHINE [75] Inventor: TakayaTadokoro, Chibashi, Japan [73] Assignee: Tsukishima Kikai Co., Ltd.,Tokyo,

Japan [22] Filed: July 27, 1973 [21] Appl. No.: 383,180

[30] Foreign Application Priority Data July 28, 1972 Japan 48-75596 [52]US. Cl 233/24, 74/404.5, 318/367 [51] Int. Cl B04b 9/10 [58] Field ofSearch 233/23 R, 23 A, 24, 25,

[56] References Cited UNITED STATES PATENTS 2,129,992 9/1938 De Mattiau..233/23R 2/l958 Sinn 233/25 X 11/1969 Strohmaier 233/23 R PrimaryExaminerGeorge H. Krizmanich Attorney, Agent, or Firm'Edwin E. Greigg [57 ABSTRACT 9 Claims, 7 Drawing Figures PATENTELBEE 319M I 3,851,818

SHEET 20F 6 FlG.2.

PATENTL; M 31 14 SHEEI 0F 6 PATENTEL DEC 1 74 saw 80F a DRIVING DEVICEFOR ROTARY CHEMICAL MACHINE This invention relates to a driving devicefor a rotary chemical machine, and more particularly to an improveddriving device for a rotary chemical machine such as centrifugalseparator which will automatically operate under predetermined operatingconditions.

A rotary chemical machine, such as centrifugal separator, particularly acentrifugal separator of the type having a discharger for dischargingoff the muddy material out of a separating basket thereof, ordinarilyneeds to be rotated at two different rotating speeds at least, such as,at high speed in low torque for separating liquid from solid materialand at low speed in high torque for discharging solid material out ofthe separating basket. The conventional centrifugal separator having ascrathing edgehas two driving devices. One of these is a driving devicehaving two prime motors-a high-speed prime motor for driving in highspeed range and a low-speed prime motor for driving in low speed range.The other is the type having only one prime motor such as variable speedprime motor such as DC. electric motor, multi-pole induction motor orhydraulic motor.

The conventional driving device is suited for driving the centrifugalseparator only in so far as its ability ti drive the separating basketat two different rotating speeds in as concerned, but in designing theconventional driving device, no due consideration is given to thebelow-mentioned operating conditions peculiar to the centrifugalseparator and therefore, the design fails to give adequate performance.

That is, the centrifugal separator needs to be operated in varioustorque and at various rotating speeds responsive to the moisture,viscosity of the fluid materials to be treated and quantity to betreated; but the conventional centrifugal separator does not satisfysuch operating conditions. This is because the conventional drivingdevice for the centrifugal separator is equipped with a prime motorwhich is ordinarily an induction electric motor having constant rotatingspeed, D.C. electric motor having variable speed characteristics, ormulti-pole induction electric motor having step speed characteristics,but even if these prime motor could vary its speed, its output torquecannot be freely varied, and accordingly, the conventional drivingdevice, which transmits the rotation of the prime motor directly to thebasket, can not be well adapted for the afore-mentioned unique operatingconditions of the centrifugal separator. Therefore, such conventionaldriving device of the centrifugal separator drives the basket withexcessive torque in some cases, and with less excessive torque in othercases. This applies excessive load to the prime motor and itstransmitting mechanism, and it is also difficult to operate the deviceas desired.

It is, therefore, an object of the present invention to provide animproved driving device for a rotary chemical machine, which may befreely preset to the operating conditions of the machine.

It is another object of the present invention to provide a drivingdevice for a rotary chemical machine such as a rotary centrifugalseparator which is automatically operated under preset operatingconditions.

It is another object of the present invention to provide a drivingdevice for a rotary chemical machine such as a rotary centrifugalseparator which is automatically operated under presetoperatingconditions.

It is a further object of the present invention to provide a drivingdevice for a rotary chemical machine which generates variable torqueresponsive to the load at the output shaft of the driving device.

It is still another object of the present invention to provide a drivingdevice for a rotary chemical machine such as a centrifugal separatorwhich may prevent the excessive load from being transmitted to thedriving device.

It is still another object of the invention to provide a driving devicefor a rotary chemical machine such as a centrifugal separator which mayprovide a low torque high speed operation for separating liquid fromslurry and a high torque low speed operation for discharging solidmaterial out of the basketwith one prime motor.

These and other objects of this invention, as hereinafter will readilybecome apparent, are provided by a driving device for a rotary chemicalmachine having a rotary basket, normally and reversely rotatable, and arotary shaft affixed to the rotary basket, which comprises a reversibleprime motor having a cylindrical hollow input shaft driven thereby, anoutput shaft secured to said rotary shaft, a rotary casing rotatablymounted around said output shaft, a first one-way clutch interposedbetween the input shaft of said prime motor and said rotary casing forcoupling the input-shaft of said prime motor to said rotary casing whenthe input shaft rotates in one direction, a second one-way clutchinterposed between the input shaft of said prime motor and said outputshaft for coupling the input shaft to said output shaft when the inputshaft rotates in the other direction,.a reduction gear mechanismcontained in said rotary casing and having a first sun gear integrallyformed on said output shaft, a sleeve shaft rotatably mounted on thesaid output shaft coaxially adjacent to the sun gear and having a secondsun gear integrally formed thereon adjacent to the said first sun gearand ,projecting externally of said rotary casing, a stub shaft mountedaround said output shaft, so as to be rotatable about its own axis andalso around said output shaft within said rotary casing, first andsecond planetary idle gears rotatably mounted on said stub shaft andengaged with said first sun gear and said second sun gear respectively,and driven separately from said rotary casing only when said input shaftof said prime motor is rotated in one direction, a torque controlmechanism having a non-restricting element fixedly secured to theprojected end of said sleeve shaft at least one pair of braking elementsmovable relative to each other toward or away from both surfaces of saidnon-restricting element so as to engage the same braking element drivecontrol means including a dual-operated air cylinder for actuating saidbraking elements, control means includinga solenoid valve forcontrolling the quality of air supply to said air cylinder and a controlcircuit for actuating said solenoid valve and having an electric motorload detector for detecting the amplitude of the load current of saidprime motor, a control for urging said braking elements into engagementwith said nonrestricting element at a desired force, and a controlcalculator for comparing the detected value detected by said loaddetector with a preset value preset by said control for producing theoutput responsive thereto for controlling the drive of said brakingelements so as to impart a desired torque to said output shaft. When thesleeve shaft of the reduction gear mechanism is restricted properly, bybraking the non-restricting element, the rotary casing is rotated sothat the stub shaft is accordingly rotated around the output shaft andrelative to the second sun gear and the second planetary idle gearmeshed with the second sun gear with the result that the stub shaft isrotated about its own axis, and therefore the rotation of the rotaryshaft is transmitted through the sleeve shaft, first and secondplanetary idle gears to the first sun gear so that the output shaft isrotated by the torque proportional to the force restricting the sleeveshaft. Thus, various torques may be produced at the output of thedriving device for the rotary chemical machine.

Another aspect of the driving device for the rotary chemical machine, isattained by the provision of means for slidably alternating theoperating position of said braking elements of said torque controlmechanism. Thus, very broad range of torque may be provided bydisplacing the position of the braking elements as they engage thenon-restricting element at the output shaft of the driving device.

According to a further aspect of the present invention, there isprovided a driving device for the rotary chemical machine whichcomprises an electric braking 'mechanism instead of the previouslydescribed mechanical braking mechanism. Thus, the wear of the brakingelements is avoided, and service and maintenance are reduced.

According to still anotheraspect of the present invention, there is alsoprovided a driving device for the rotary chemical machine having arotary basket normally and reversely rotatable and a rotary shaftaffixed to the rotary basket, which comprises a reversible prime motorhaving an input shaft driven thereby, an

output shaft secured to said rotary shaft and having a first armradially projected therefrom, a rotary casing rotatably mounted aroundsaid output shaft, a driving sun gear integrally formed onsaid driventiming wheel to the driven by the belt, a sleeve shaft rotatably mountedon said output shaft coaxially adjacent to the sun gear and having asecond arm radially projected therefrom and a second sun gear integrallyformed thereon, a first stub shaft mounted around said output shaft soas to be rotatable about its own axis and also around said output shaftwithin said rotary casing and also mounted in such a manner that thesecond arm of said sleeve shaft is coupled to the first stub shaft, asecond stub shaft so mounted around said output shaft as to be rotatableabout its own axis and also around said output shaft within said rotarycasing and also mounted in such a manner that the first arm of saidoutput shaft is complete to the second stub shaft, one-way clutchmounted at the projected end of said second stub shaft, first andsecondring gears formed on the inner periphery of said rotary casingcorresponding to said first and second sun gears respectively, first andsecond idle planetary gears rotatably mounted on the first and secondstub shafts, respectively, intermeshing with the first sun and ringgears and second sun and ring gears', respectively, in such a mannerthat the one-way clutch couples the second planetary gear with thesecond stub shaft when the input shaft is rotated in one direction andthe one-way clutch .disengages the second planetary gear from the secondstub shaft when the input shaft is rotated in the other direction, atorque control mechanism having a non-restricting element formed on therotary casing as an extension of one wall thereof for rotation therewithof at least one pair of braking elements movable relative to each othertoward or away from both surfaces of said non-restricting'element.

According to still another embodiment of the present invention, there isprovided a driving device for the rotary chemical machine having arotary basket and a rotary shaft secured thereto which comprises areversible prime motor having a first high speed input shaft driventhereby and second low speed input shaft driven thereby, an output shaftsecured to said rotary shaft which is connected to the same reductiongear mechanism as described in the immediately preceding paragraph, ie,the rotary casing containingthe embodiment mechanism and the outputshaft for disengaging the coupling of the gear mechanism to the outputshaft only when the first high speed driven timing wheel is coupled withthe output shaft by the first one-way.

clutch, the third one-way clutch being mounted between the second lowspeed driven timing wheel and the planetary gear mechanism for couplingthe second low speed driven timing wheel with'the planetary gearmechanism only when the second driven timing wheel is rotated in onedirection, a torque control mechanism having a non-restricting elementformed on the rotary casing as an extension of one wall thereof forrotation thereforth, and at least one pair of braking elements movablerelative to each other toward or away from both surfaces of saidnon-restricting element.

These andother objects, features and advantages'of the present inventionwill become more fullyapparent from the following description given inconjunction with the accompanying drawings, in which:

FIG. I is a schematic view of one embodiment of a driving device for arotary chemical machine according to the present invention;

FIGS. 2 to 4 are enlarged sectional views of the driving device for therotary chemical machine constructed in detail of the device in FIG. 1;

FIG. 5 is a schematic view of another embodiment of the driving devicefor the rotary chemical machine constructed according to the presentinvention;

FIG. 6 is a partial sectional view of the driving device constructed indetail of the device in FIG. 5; and

FIG. 7 is a schematic view of still another embodiment of the drivingdevice for the rotary chemical machine of the present invention.

Reference is now made to the drawings, and particularly to FIG. 1, whichschematically shows the entire structure of one embodiment of 'acentrifugal separator with abasket having a driving device constructedaccording to the present invention.

This separator has a basket 2 fixed to the lower end of a verticallyextended rotary shaft 1 and rotatable together as generally well known.The upper end of the rotary shaft 1 is rotatably supported by bearings 5within a bearing box 4 fixed to a frame 3, and is connected to the lowerend of an output shaft 7 through a coupling 6 so that the vibration ofthe basket 2 may not be transmitted thereto. A driving device, generallydesignated by numeral 8, comprises a reduction gear mechanism, generallydesignated by numeral 9, and a torque control mechanism 10, and isconnected to only one reversible prime motor M such as, for example, anordinary electric induction motor through a pair of clutches 11 and 12and a starter compensating mechanism 13.

The driving device 8 comprises a rotary casing 14 which contains thereduction gear mechanism 9 such as a planetary gear mechanism and whichis rotatably mounted around the output shaft 7 having the shaft coupling6 at one end thereof.

The torque control mechanism 10 is for the purpose of imparting adesired torque to the output shaft 7 and comprises a control mechanismincluding a nonrestricting element for restricting part of the drivingdevice 8 such as, for example, a brake disc 15.

The starter compensating mechanism 13 is for the purpose of preventingan overload from being applied to the electric motor M when starting themotor M, and may be, for example, a centrifugal clutch or any well knownfluid clutch.

Referring now to FIGS. 2 and 3, in the driving device constructedaccording to the first embodiment of the present invention numeralrl6denotes a cylindrical hollow input shaft driven through the startercompensating mechanism (not shown for clarity in depicting the inventionin these figures) by the reversable motor M and connected through a pairof one-way clutches 11 and 12 to a rotary casing 14 and the output shaft7. The one-way clutch ll interposed between the input shaft 16 and therotary casing 14 couples the input shaft 16 to the rotary casing 14 whenthe input shaft 16 rotates in one direction, while the one-way clutch 12disposed between the input shaft 16 and the output shaft 7 couples theinput shaft 16 to the output shaft 7 when the input shaft 16 rotates inthe other direction. The output shaft 7 is formed integrally with a sungear 17 forming part of the gear mechanism within the rotary casing 14,and is supported by bearings 18 within the rotary casing 14 so as to befreely rotatable with respect to the rotary casing 14. A sleeve shaft 20formed integrally with a sun gear 19 coaxially adjacent to the sun gear17 is rotatable through needle bearings 21 on the output shaft 7, andone end of the sleeve shaft 20 projects externally from the rotarycasing 14, and part of the torque control mechanism such as, forexample, the brake disc is affixed to the flange 22 formed at theprojecting end.

There are provided planetary idle gears 23 and 24 rotatably mounted on astub shaft 25 and engaged with the sun gear 17 and the sun gear 19respectively, within the rotary casing 14, and both ends of the stubshaft 25 are rotatably supported at the upper and lower end portionsthrough needle bearings 26 provided within the rotary casing 14.

It will be understood now that when the input shaft 16 is rotated in onedirection so that the one-way clutch 11 now acts to drive the rotarycasing 14, this casing is then rotated in the same direction as that ofthe input shaft 16, and therethrough the idle planetary gears 23 and 24rotatably engaged with the stub shaft 25 tend to rotate in intermeshingengagement with the sun gears 17 and 19, respectively, formed on theoutput shaft 7. However, since the reaction force necessary to rotatethe planetary idle gear 24 by the sun gear 19 is not available since thesleeve shaft 20 is not restricted at this time, the planetary idle gear24 cannot rotate with the result that the stub shaft 25 may notaccordingly rotate about its own axis, but will rotate around the outputshaft 7 integral with the rotary casing 14 and sleeve shaft 20. That is,the output shaft 7 may not be rotated in this mechanism unless thesleeve shaft 20 is not restricted.

If the sleeve shaft 20 is, however, restricted by a proper force so asnot to rotate, the rotation of the rotary casing 14 rotates the stubshaft 25 around the output shaft 7 and simultaneously relatively rotatesbetweenthe sun gear 19 and the planetary idle gear 24, and therebyrotates the stub shaft 25 about its own axis.

Therefore, the rotation of the rotary casing 14 is, in this case,transmitted through the sleeve shaft 20 and planetary idle gears 24 and23 to the sun gear 17 with the result that the output shaft 7 is rotatedby the torque proportional to the force restricting the sleeve shaft 20.

When the input shaft 16 is driven in reverse to the rotating directionas described above, clutch 11 is disengaged, and at the same time theother clutch 12 is actuated, and thereby the input shaft 16 drives withthe output shaft 7. Accordingly, the output shaft 7 transmits,

in this case, the torque of the input shaft 16 directly. It is readilyunderstood from the foregoing description that if the sleeve shaft 20 isrestricted by a predetermined restricting force, various torques may beproduced at the output shaft 7.

According to the present invention, the contrifugal separator isprovided with a torque control mechanism for producing various amountsof torque at the output shaft 7 by varying the restricting forceimparted to the sleeve shaft 20 responsive to the operating conditionsof the centrifugal separator.

As further exemplified in FIGS. 2 and 3, the torque control mechanism isarranged to engage the oppositely disposed surfaces of the control disc15 and comprises several pairs of braking elements 27, 27 (one pair ofbraking elements being illustrated in FIGS. 2 and 3) which are movablerelative to each other to control the rotation of disc 15. The drivecontrol device in particular has a dual-operated air cylinder 28, and acontrol device 29 therefore which controls the disc 15. The controldevice 29 includes in the embodiment shown in FIG. 2, a solenoid valve30 for controlling the quantity of air supplied to the air cylinder 28and a circuit for controlling the opening of the solenoid valve 30. Thecircuit includes an electric motor load detector 31 for detecting theamplitude of the load current of the electric motor M which is the inputshaft 16. The control 32 for operation of the braking elements 27, 27 iscoordinated with a control calculator 33 which compares the valuedetected by the load detector 31 with a preset value established by thecontrol to produce the output responsive thereto.

From the foregoing description of this embodiment of the invention, itwill now be understood that when a muddy solid substance adheres ontotheinner wall of the basket 2 of the separator is discharged by adischarger,the following torque may be imparted to the output shaft 7 bythe torque control mechanism 10.

More particularly, when the electric motor M is started after presetvalues predetermined by the control 32, which preset valves aredetermined by the state of the moisture content of the substance to betreated, grain size, viscosity, desired percentage of moisture contentafter separation, and operating hours, the control signal responsive tothe preset values is imparted to the solenoid valve 30 which is thenopened with the result that the braking elements 27, 27 are urged intocontact with the brake disc with a predetermined pressure. Therefore,the braking torque which corresponds to the force applied to the brakingelements 27 27 acts on the sleeve shaft 20, and the output shaft 7 isrotated by the torque corresponding to the preset value. Thus, if anexcessive load is applied to the electric motor M during operation, byany cause, the solenoid valve 30 is controlled by the detected signalfrom the detector'31 with the result that the transmission of theexcessive load to the electric motor M and to entire drive device isprevented.

The alternative embodiment of a control device for controlling thetorque applied to the output shaft 7 is shown in FIG. 3 and is broaderthanthe device shown in FIG. 2. The control device of FIG. 3 comprises adevice for alternating the operating position of the braking element 27,27. This device includes an electric motor control 34, a screw shaft 35directly coupled to the electric motor 34 and a slider 37 having a nutportion 36 threadable on the screw shaft 35, for movement of slider 37positioned to slide on a stationary base 38 radially adjacent of thebrake disc 15. The electric motor control 34 is connected to the controlcalculator 33 of the control circuit, and is controlled by the signaltherefrom.

According to the aforementioned description of this embodiment of thedriving device, it can be seen that as the braking elements 27, 27 arecapable of being moved radially of the brake disc 15, a very broad rangeof torques may be applied to the output shaft 7.

FIG. 4 shows still another embodiment of the control device forcontrolling the torque applied to the output shaft of this invention.The device of this embodiment comprises an electric braking mechanisminstead of the mechanical braking mechanism designated in FIGS. 2 and 3in order to avoid the wear of the braking element and to reduce thenecessity of service and maintenance thereof. This braking conceptcomprises an eddy current mechanism generally called eddy currentretarder, and includes a pair of electromagnetic poles 39, 39 which aredisposed opposite sides of the brake disc 15. The poles 39, 39 areconnected to the control calculator 33 of the control circuit in amanner similar to the solenoid 30 previously described and is controlledby the output signal value of the control calculator 33.

According to this embodiment of the control device an eddy current isgenerated on the brake disc 15 by means of a magnetic flux generated bythe poles 39, 39 and accordingly, a reaction torque is applied to thebrake disc 15 with the result that the disc 15 is braked. It will bereadily understood that since the braking force is proportional to theamplitude of the eddy current, i.e., the strength of the magnetic fluxdensity generated by the poles 39, 39, the strength ofthe torque appliedto the output shaft 8 may be varied responsive to the amplitude of thecontrol signal for energizing the poles 39, 39.

Turning now to FIG. 5 which is a schematic illustration of anotherembodiment of this invention for a basket type centrifugal separator, itcan be seen that the driving device 8 comprises a driven timing wheel40, which is driven by a reversible electric motor M provided on theframe 3 through a drive timing wheel 41 and a belt 42. The drivingdevice 8 is substantially the same as those shown in FIGS. 2 to 4, butis varied as best seen in detail in FIG. 6, the description of whichfollows later.

Thedriving device 8 comprises a rotary casing 14 similar to the drivingdevice designated in FIGS. 2 to 4, but is constructed somewhatdifferently. These ring gears 45 and 46 form a planetary gear mechanism9, together with a pair of planetary gears which will be hereinafterdescribed in greater detail.

The lower end of an output shaft 7 in the center of the rotary casing 14is relatively rotatably supported with respect to the rotary casing 14by a thrust bearing 47 provided at the lower end of the rotary casing14, whilethe other end projects outwardly of the upper end of the casingl4'and is connected to the main shaft 1 of the basket by means of theshaft coupling 6 shown in FIG. 5.

Beneath the coupling 6, there is provided on the output shaft 7, aninput sleeve shaft 16 supported by bearings 48 and a reduction gearsleeve shaft 50 supported by bearings 49 with each sleeve being capableof rotation separately and independently of each other. The sleeve shaft16 is rotatably supported relative to the casing 14 by bearings 51 so asto be driven by the reversable electric motor M shown in FIG. 5 by meansof the driven time wheel 40 secured to the end of the input shaft 16.The reduction gear shaft 50 has an arm 52 extending radially from oneend thereof and a sun gear (hereinafter called the second sun-gear)coaxially with the shaft 50-at the other end. Secured to the arm 56 isone end of a stub shaft 54 having an axis parallel with the input sleeveshaft 16 and output shaft 7, and

. at the other end of the stub shaft 54 is a first planetary gear 56rotatably supported by bearings 55. The first planetary gear meshes witha planetary sun-gear 57 provided on the input sleeve shaft 16 and alsowith the first ring-gear 45 provided on the inner wall of the rotarycasing 14. An arm 58 extends radially of the shaft '7 in the vicinity ofthe bearing 47 and is provided with a second short stub shaft 59 alignedon the same axis as the first stub shaft 54 and provided with aone-wayclutch 60 and a second planetary gear 61 which meshes with the secondplanetary ring-gear 46 on rotary casing 14 and with the second sun-gear53. This one-way clutch 60 couples the second planetary gear 61 with thesecond short stub shaft 59 when the input sleeve shaft 16 is rotated asdesignated by arrow A which rotates the second planetary gear 61oppositely to the direction designated by the arrow A, while the one-wayclutch 60 disengages the second planetary gear 61 from the second shortstub shaft 59 when the input shaft 16 is rotated oppositely to thedirection as illustrated by the arrow A, which, of course, rotates thesecond planetary gear 61 in the direction illustrated by the arrow A.

' In this embodiment the braking of either of the disc 15, 15 formed asan extension on the top or bottom walls of the rotary casing 14 isaccomplished in the same manner as described earlier in connection withFIG. 1.

In the above described embodiment, assuming now that the input shaft 16is rotated in the direction designated by an arrow A in FIG. 6, theone-way clutch 60 couples the second planetary gear 61 with the secondshort stub shaft 59, and neither of the brake discs 15 are restricted bythe braking elements 27, 27. In this case there is no relative rotationbetween the second planetary gear 61 and the second short stub shaft 59with the result that the second planetary gear 61 is restricted so asnot to rotate around its own axis, i.e., about the second short stubshaft 59. Since relative rotation of the second planetary gear 61 isstopped, the second ring gear 46 and second sun gear 53 on the reductiongear shaft 50 is held in unison with the output shaft 7, and is thenstopped. Therefore, at this time the first planetary gear 56 meshed withthe first sun gear 57 tends to transmit rotary torque opposite to therotation of the first sun gear 57. However, since the first ring gear 45meshes with the first planetary gear 56 and rotary casing 14 is held inunison by the second planetary gear 61 the action of the clutch 60, atthis time, the above rotary torque may not rotate the first planetarygear 56 about the first short stub shaft 54 and accordingly the rotationof the input sleeve shaft 16 is transmitted directly to the rotarycasing 14' held in unison with the output shaft 7. Therefore, in thiscase, the output shaft 7 and rotary casing 14 are rotated directlytogether with the input sleeve shaft 16 in the state integration withthe input shaft 16 and accordingly the output shaft 7 is rotated in thedirection as designated by an arrow A. Consequently, the main shaft 1 ofthe basket directly coupled with the output shaft 7 is rotated in lowtorque at high speed for separating the solids from the liquid.

When the separation of solids from the liquid within the basket iscompleted, the driving device is switched to rotation in at a hightorque at low speed for discharging the muddy substance out of thebasket by a command from the control device (not shown). This hightorque and low speed operation is executed as follows:

The electric motor M is switched to reverse drive in FIG. 5 by a drivecommand from the control device (not shown) and simultaneously thesolenoid valve 30 for operating the braking elements, is opened in apreset degree with the result that the braking elements 27, 27 are urgedonto the brake discs 15, by a predetermined pressure, and thereby therotation of the rotary casing 14 is restricted.

When the input sleeve shaft 16 is rotated in the direction designated byan arrow B, the first planetary gear 56 meshed with the first sun gear57, tends to rotate or is rotated in an opposite direction to therotating direction of the input sleeve shaft 16 about the first shortstub shaft 54. In this case, however, since the rotary casing 14 isrestricted by brakes 27, 27 as aforementioned, the first planetary gear56 may not rotate the rotary casing 14 depending on the amountof'restriction as restricting element 15, 15 but, on the contrary, thefirst planetary gear 56 is rotated clockwise around the output shaft 7meshing with the first ring gear 45 fixed to the casing 14 andaccordingly in the direction as illustrated by the arrow B with theresult that the arm 52 of the reduction gear shaft 50 supporting thefirst planetary gear 56 is rotated clockwise around the output shaft 7.Therefore, the second sun gear 53 on gear shaft 50 is also rotatedclockwise and rotary torque in the direction as designated by an arrow Afor rotating the second planetary gear 61 about the second short stubshaft 59 is transmitted to the second planetary gear 61 meshed with thesecond sun gear 53. The oneway clutch 60 is disengaged by this torque,and accordingly, the second planetary gear 61 is not coupled to thesecond short stub shaft 59, but is freely rotated about the second shortshaft 59 by the second sun gear 53. This rotation of thesecond planetarygear 61 is converted to the torque for rotating or tending to rotate therotary casing 14 in the direction as designated by the arrow A throughthe second ring gear 46. However, since the rotary casing 14 isrestricted by the braking elements 27, 27 as aforementioned, the rotarycasing 14 is not rotated or is rotated slowly depending on the amount ofrestriction by brakes 27, 27 but, on the contrary, the second planetarygear 61 is rotated in the direction as illustrated by the arrow B aroundthe second ring gear 46. As a result, the arm 58 supporting the secondplanetary gear 61 and output shaft 7 are rotated in the direction asillustrated by the arrow B.

With such a rotation of the input shaft 16 and output shaft 7 in thedirection designated by the arrow B as described above', the rotationalspeed of output shaft 7 is greatly reduced by a large ratio, andaccordingly this rotation is utilized for scratching the solid substanceadhered onto the inner wall of the basket of the centrifugal separator.I

The aforementioned principle of the present invention will be furtherperformed as various alternatives and modifications as will behereinafter described.

FIG. 7 shows still another embodiment of the driving device for thecentrifugal separator of this invention having similar functions asthose of the embodiments shown in FIGS. 1 to 6, in which the drivingdevice 8 includes three one-way clutches 62,63, and 64. This drivingdevice 8 comprises a rotary casing 14 similar to the driving deviceshown in FIG. 6 and containing a planetary gear mechanism 9, the detailof which is omitted in FIG. 7, within the rotary casing 14. Thisplanetary gear mechanism 9 is connected through the three one-wayclutches 62, 63 and 64 to. the output shaft 7, high speed driven timingwheel 65, and low speed input shaft 66. A low speed driven timing wheel67 is mounted on the low speed input shaft 66, and is connected to drivetiming wheels 69 and 70 on a drive shaft 68 directly coupled with thereversible electric motor M together with the high speed driven timingwheel 65 through V belts 71 and 72, respectively. The one-way clutch 62for coupling the driven timing wheel 65 with the output shaft 7 ismounted between the high speed driven timing wheel 65 and the outputshaft 7 only when the driven timing wheel 65 is rotated in one directionsuch as, for example, in the direction designated by the arrow A, andthe one-way clutch 64 for coupling the low speed driven timing wheel 67with the planetary gear mechanism 9 between the low speed driven timingwheel 67 and the planetary gear mechanism 9 only when the driven timingwheel 67 is rotated in one direction such as, for example, in thedirection illustrated by an arrow A. In addition, another one-way clutch63 is interposed between the planetary gear mechanism 9 and the outputshaft 7, and disengages the-connection of the planetary gear mechanism 9to the output shaft 7 only when the high speed driven timing wheel 65 iscoupled with the output shaft 7 by the one-way clutch 62.

The rotary casing 14 is connected to the torque control mechanism forimparting a desired torque to the output shaft 7 by restricting thebraking elements 15, such as brake discs mounted to the casing 14similar to the embodiment shown in FIG. 6. Since this torque controlmechanism is entirely the same as that shown in FIGS. 2 and 3, thedetails are omitted.

Assuming now that liquid suspension material such as mud is poured intothe basket 2 in the device shown in FIG. 7, and the separator is rotatedso as to separate the liquid from the material.

The drive electric motor M rotates the drive timing wheel 69 in thedirection designated by the arrow A so that the rotation of the drivetiming wheel 69 rotates the high speed driven timing wheel 65 in thedirection illustrated by an arrow A through the V belt 71. When the highspeed driven timing wheel 65 is so rotated the one way clutch 62interposed between the high speed driven timing wheel 65 and the outputshaft 7 couples the timingwheel 65 with the output shaft 7, while theone-way clutch 63 interposed between the planetary gear mechanism 9 andthe output shaft 7 disengages the connection of the output shaft 7 tothe planetary gear mechanism 9. In this case, through the low speeddriven timing wheel 67 is simultaneously rotated in the same directionas that of the high speed driven timing wheel 65, the one-way clutch 64interposed between the low speed input shaft 66 andthe planetary gearmechanism 9 is not operated and accordingly the low speed input shaft 66is not connected to the planetary gear mechanism 9 and consequently thelow speed input shaft 66 is idled with respect to the planetary gearmechanism 9. As a result, the output shaft 7 is rotated at high speedfrom the high speed driven timing, wheel 65 directly, and the basket 2for the separator is also rotated at high speed in the direction asdesignated by an arrow A. When the basket 2 is rotated for a presetperiod so that the fluid material within the basket 2 is removed, thedrive electric Motor M is reversely driven by the command from thecontrol device (not shown), and at the same time, the braking elementl5, 15 is restricted by the torque control mechanism 10 with apredetermined force by the command from the control device. The highspeed driven timing wheel 65 is oppositely driven to the direction asdescribed above, that is opposite to the direction designated by thearrow A, and thereby the clutch 62 is disengaged so that the driventiming wheel 65 is idled about the output shaft 7. Since the low speeddriven timing wheel 67 is driven opposite to the direction as designatedby the arrow A at this time, the input shaft 66 is also rotated in thesame direction with the result that the input shaft 66 and the planetarygear mechanism 9 are coupled by the one-way clutch 64. The rotationtransmitted through the one-way clutch 64 to the planetary gearmechanism 9 operates the one-way clutch 63 with the result that theplanetary gear mechanism 9 and the output shaft 7 are coupled with eachother by the one-way clutch 63. That is, although the planetary gearmechanism 9 tends to rotate the rotary casing 14, since the rotarycasing 14 is restricted by the torque control mechanism 10 through thebraking element 15, the rotary casing 14 is not rotated or is rotatedvery little depending upon the amount of restriction by the brakingelements 27, 27 but the planetary gear mechanism 9 is rotated around theoutput shaft 7 within the rotary casing l4.similar to the case of thedevice shown in FIG. 6. As-a result, since the one-way clutch 63 isrotated around the output shaft 7 opposite to the direction asdesignated by the arrow A, the one-way clutch 63 is operated so that theplanetary gear mechanism 9 and the output shaft 7 are coupled together.Thus, the low speed rotation transmitted to the input shaft 66 isfurther reduced through the planetary gear mechanism 9 and. istransmitted to the output shaft 7 so as to rotate the output shaft 7 atlow speed in high torque/In this case, as

aforementioned, since the planetarygear mechanism 9 and the rotarycasing 14 are constructed substantially similar to those of the deviceshown in FIG. 6, it is readily understood from the foregoing descriptionthat the torque proportional to the force for restricting the rotarycasing 14 is applied to the output shaft 7.

From the foregoing description, it will now be apparent that the presentinvention provides a driving device for rotary chemical machine such ascentrifugal separator, which improves the conventional machine whichcould not heretofore be operated at optimum for the operating conditionsso as to enable the machine to operate at optimum levels according tothe operating conditions of the machine. A

Having now generally described the invention, a further understandingcan be attained by reference to certain specific examples which areprovided herein for purpose of illustration only and are-not intended tobe limiting in any manner the scope of the alternative applications ofthe present invention unless otherwise so specified. For example, thevariable torque operation is applied only in low speed operation of thedevice of the embodiment of the present invention, but this variabletorque operation may also be applied to high speed operation within thespirit of the present invention.

What is claimed is: e

l. A driving device for a rotary chemical machine having a normally andreversely rotatable rotary basket and a rotary shaft affixed to therotary basket, comprising a reversible prime motor having a cylindricalhollow input shaft driven thereby, an output shaft secured to saidrotary shaft, a rotary casing rotatably mounted around said outputshaft, a first unidirectional clutch interposed between the input shaftof said prime motor and said rotary casing for coupling the input shaftof said prime motor to said rotary casing when the input shaft rotatesin one direction, a second unidirectional clutch interposed between theinput shaft of said prime motor and said output shaft secured throughthe rotary shaft to said rotary basket for coupling the input shaft tosaid output shaft when the input shaft rotates in the other direction, areduction gear mechanism contained in said rotary casing and having afirst sun gear integrally formed on said output shaft, a sleeve shaftrotatably mounted on said output shaft coaxially adjacent to the sungear and having a second sun gear integrally formed thereon adjacent tosaid first sun gear, and further having one end thereof projectedexternally from said rotary casing, a stub shaft so mounted around saidoutput shaft, so as to be rotatable about its own axis and also aroundsaid output shaft within said rotary casing, first and second idleplanetary gears rotatably mounted on said stub shaft and engaged withsaid first sun gear and second sun gear respectively and drivenseparately from said rotary casing only when-said input shaft of saidprime motor is rotated in one direction, a torque control mechanismhaving a non-restricting element affixed to the projected end of saidsleeve shaft, at least one pair of braking elements movable relative toeach other toward or away from both surfaces of said non-restrictingelement, braking element drive'control means including a dual-operatedair cylinder for actuative said'braking elements, control meansincluding a solenoid valve for controlling the quantity of air suppliedto said air cylinder and a control circuit for controlling the openingof said solenoid valve and having an electric motor load detector fordetecting the amplitude of the load current of said prime motor, acontrol for urging said braking elements into engagement with saidnon-restricting element by a desired force, and a control calculator forcomparing the detected value detected by said load detector with apreset value preset by said control for producing the output responsivethereto for controlling the actuation of said braking elements so as toimpart a desired torque to said output shaft.

2. A driving device according to claim 1, further comprising means foralternating slidably the operating position of said braking elements ofsaid torque control mechanism and having a control electric motor, ascrew shaft directly coupled to said control electric motor and a sliderhaving a nut portion threaded on the screw shaft and so placed as toslide on a stationary base radially of said braking elements.

3. A driving device according to claim 1, wherein said braking mechanismis an eddy current braking mechanism which comprises a pair ofelectromagnetic poles disposed on opposite surfaces of the brakeelement, and a control calculator connected to said poles forcontrolling the electromagnetic poles.

4. A driving device for the rotary chemical machine having a rotarybasket normally and reversely rotatable and a rotary shaft affixed tothe rotary basket, comprising a reversible prime motor having an inputshaft driven thereby, an output shaft secured to said rotary shaft andhaving a first arm radially projected therefrom, a rotary casingrotatably mounted around said output shaft, a driving timing wheeldriven by the reversible prime motor through a belt with a driven timingwheel mounted on the output shaft, a reduction gear mechanism containedin said rotary casing and having a first sun gear integrally formed onsaid driven timing wheel, a sleeve shaft rotatably mounted on saidoutput shaft coaxially adjacent to the sun gear and having a second armradially projected therefrom and a second sun gear integrally formedthereon, a first stub shaft so mounted around said output shaft so as tobe rotatable about its own axis and also around said output shaft withinsaid rotary casing in such a manner that the second arm of sleeve shaftis coupled to the first stub shaft, a second stub shaft mounted aroundsaid output shaft so as to be rotatable about its own axis and alsoaround said output shaft within said rotary casing in such a manner thatthe first arm of said output shaft is coupled to the second stub shaft,one-way clutch mounted on said second stub shaft, first and second ringgears formed on the inner periphery of said rotary casing correspondingto the first and second sun gears of said driven timing wheel and sleeveshaft, respectively, first and second idle planetary gears rotatablymounted on the first and second stub shafts, respectively, in meshingengagement wit the first sun and ring gears and second sun and ringgears, respectively,

in such a manner-that the one-way clutch couples the second planetarygear with the second stub shaft when the input shaft is rotated in onedirection and the oneway clutch disengages the second planetary gearfrom the second stub shaft when the input shaft is rotated in the otherdirection, a torque control mechanism having a non-restricting elementon the rotary casing, at least one pair of braking elements movablerelative to each other toward or away from both side surfaces of saidnon-restricting element.

5. The driving device according to claim 4, further comprising means foralternating slidably the operating position of said braking elements ofsaid torque control mechanism and having a control electric motor, ascrew shaft directly coupled to said control electric motor and asliderhaving a nut portion threaded on the screw shaft and so placed as toslide on a stationary base radially of said braking elements.

6. The driving device according to claim 4, wherein said brakingmechanism is an eddy current braking mechanism which comprises a pair ofelectromagnetic poles disposed on opposite surfaces of the brake elementand a control calculator connected to said poles for controlling theelectromagnetic poles.

7. A driving device for the rotary chemical machine having a rotarybasket normally and reversely rotatable and a rotary shaft affixed tothe rotary basket, comprising a reversible prime motor having a firsthigh speed input shaft driven thereby and second low speed input driventhereby, an output shaft secured to said rotary shaft and having a firstarm radially projected therefrom, a rotary casing rotatably mountedaround said output shaft, a first driving timing wheel driven by thereversible prime motor through a first belt with a first high speeddriven timing wheel mounted on the output shaft and a second drivingtiming wheel driven by the reversible prime motor through a second beltwith a second low speed driven timing wheel mounted on the second lowspeed input shaft, a reduction gear mechanism contained in said rotarycasing and having a first sun gear integrally formed on said firstdriven timing wheel, a sleeve shaft rotatably mounted on said outputshaft coaxially adjacent to the sun gear and having a second armradially projected therefrom and a second sun gear integrally formedthereon, a first stub shaft so mounted around said output shaft as to berotatable about its own axis and also around said output shaft withinsaid rotary casing in such a manner that the second arm of said sleeveshaft is coupled to the first stub shaft, a second stub shaft so mountedaround said output shaft as to be rotatable about its own axis and alsoaround said output shaft within said rotary casing in such a manner thatthe first arm of said output shaft is coupled to the second stub shaft,first one-way clutch mounted between the first high speed driven timingwheel and the output shaft for coupling only when the first driventiming wheel is rotated in one direction, first and second ring gearsformed on the inner periphery of said rotary casing corresponding to thefirst and second sun gears of said first driven timing wheel and thesleeve shaft, respectively, first and second idle planetary gearsrotatably mounted on the first and second stub shafts, respectively, inmeshing engagement with the first sun and ring gears and second sun andring gears, respectively, a second oneway clutch mounted between theplanetary gear mechanism and the output shaft for disengaging theconnection of the planetary gear mechanism to the output shaft only whenthe first high speed driven timing wheel is coupled with the outputshaft by the one-way clutch, a third one-way clutch mounted between thesecond low speed driven timing wheel and the planetary gear mechanismfor coupling the second low speed driven timing wheel with the planetarygear mechanism only when the second driven timing wheel is rotated inone direction, a torque control mechanism having a non-restrictingelement on the rotary casing, at least one pair of braking elementsmovable relative to each other toward or away from both side surfaces ofsaid non-restricting element.

8. The driving device according to claim 7 further comprising means foralternating slidably the operating position of said braking elements ofsaid torque control mechanism and having a control electric motor, ascrew shaft directly coupled to said control electric motor and a sliderhaving a nut portion threaded on the screw shaft and so placed as toslide on a stationary base radially of said braking elements.

9. The driving device according to claim 7 wherein said brakingmechanism is an eddy current braking mechanism which comprises a pair ofelectromagnetic poles disposedon opposite surfaces of the brake elementand a control calculator connected to said poles for controlling theelectromagnetic poles.

1. A driving device for a rotary chemical machine having a normally andreversely rotatable rotary basket and a rotary shaft affixed to therotary basket, comprising a reversible prime motor having a cylindricalhollow input shaft driven thereby, an output shaft secured to saidrotary shaft, a rotary casing rotatably mounted around said outputshaft, a first unidirectional clutch interposed between the input shaftof said prime motor and said rotary casing for coupling the input shaftof said prime motor to said rotary casing when the input shaft rotatesin one direction, a second unidirectional clutch interposed between theinput shaft of said prime motor and said output shaft secured throughthe rotary shaft to said rotary basket for coupling the input shaft tosaid output shaft when the input shaft rotates in the other direction, areduction gear mechanism contained in said rotary casing and having afirst sun gear integrally formed on said output shaft, a sleeve shaftrotatably mounted on said output shaft coaxially adjacent to the sungear and having a second sun gear integrally formed thereon adjacent tosaid first sun gear, and further having one end thereof projectedexternally from said rotary casing, a stub shaft so mounted around saidoutput shaft, so as to be rotatable about its own axis and also aroundsaid output shaft within said rotary casing, first and second idleplanetary gears rotatably mounted on said stub shaft and engaged withsaid first sun gear and second sun gear respectively and drivenseparately from said rotary casing only when said input shaft of saidprime motor is rotated in one direction, a torque control mechanismhaving a non-restricting element affixed to the projected end of saidsleeve shaft, at least one pair of braking elements movable relative toeach other toward or away from both surfaces of said non-restrictingelement, braking element drive control means including a dual-operatedair cylinder for actuative said braking elements, control meansincluding a solenoid valve for controlling the quantity of air suppliedto said air cylinder and a control circuit for controlling the openingof said solenoid valve and having an electric motor load detector fordetecting the amplitude of the load current of said prime motor, acontrol for urging said braking elements into engagement with saidnon-restricting element by a desired force, and a control calculator forcomparing the detected value detected by said load detector with apreset value preset by said control for producing the output responsivethereto for controlling the actuation of said brakinG elements so as toimpart a desired torque to said output shaft.
 2. A driving deviceaccording to claim 1, further comprising means for alternating slidablythe operating position of said braking elements of said torque controlmechanism and having a control electric motor, a screw shaft directlycoupled to said control electric motor and a slider having a nut portionthreaded on the screw shaft and so placed as to slide on a stationarybase radially of said braking elements.
 3. A driving device according toclaim 1, wherein said braking mechanism is an eddy current brakingmechanism which comprises a pair of electromagnetic poles disposed onopposite surfaces of the brake element, and a control calculatorconnected to said poles for controlling the electromagnetic poles.
 4. Adriving device for the rotary chemical machine having a rotary basketnormally and reversely rotatable and a rotary shaft affixed to therotary basket, comprising a reversible prime motor having an input shaftdriven thereby, an output shaft secured to said rotary shaft and havinga first arm radially projected therefrom, a rotary casing rotatablymounted around said output shaft, a driving timing wheel driven by thereversible prime motor through a belt with a driven timing wheel mountedon the output shaft, a reduction gear mechanism contained in said rotarycasing and having a first sun gear integrally formed on said driventiming wheel, a sleeve shaft rotatably mounted on said output shaftcoaxially adjacent to the sun gear and having a second arm radiallyprojected therefrom and a second sun gear integrally formed thereon, afirst stub shaft so mounted around said output shaft so as to berotatable about its own axis and also around said output shaft withinsaid rotary casing in such a manner that the second arm of sleeve shaftis coupled to the first stub shaft, a second stub shaft mounted aroundsaid output shaft so as to be rotatable about its own axis and alsoaround said output shaft within said rotary casing in such a manner thatthe first arm of said output shaft is coupled to the second stub shaft,one-way clutch mounted on said second stub shaft, first and second ringgears formed on the inner periphery of said rotary casing correspondingto the first and second sun gears of said driven timing wheel and sleeveshaft, respectively, first and second idle planetary gears rotatablymounted on the first and second stub shafts, respectively, in meshingengagement with the first sun and ring gears and second sun and ringgears, respectively, in such a manner that the one-way clutch couplesthe second planetary gear with the second stub shaft when the inputshaft is rotated in one direction and the one-way clutch disengages thesecond planetary gear from the second stub shaft when the input shaft isrotated in the other direction, a torque control mechanism having anon-restricting element on the rotary casing, at least one pair ofbraking elements movable relative to each other toward or away from bothside surfaces of said non-restricting element.
 5. The driving deviceaccording to claim 4, further comprising means for alternating slidablythe operating position of said braking elements of said torque controlmechanism and having a control electric motor, a screw shaft directlycoupled to said control electric motor and a slider having a nut portionthreaded on the screw shaft and so placed as to slide on a stationarybase radially of said braking elements.
 6. The driving device accordingto claim 4, wherein said braking mechanism is an eddy current brakingmechanism which comprises a pair of electromagnetic poles disposed onopposite surfaces of the brake element and a control calculatorconnected to said poles for controlling the electromagnetic poles.
 7. Adriving device for the rotary chemical machine having a rotary basketnormally and reversely rotatable and a rotary shaft affixed to therotary basket, comprising a reversible prime motor having a first highspeed input Shaft driven thereby and second low speed input driventhereby, an output shaft secured to said rotary shaft and having a firstarm radially projected therefrom, a rotary casing rotatably mountedaround said output shaft, a first driving timing wheel driven by thereversible prime motor through a first belt with a first high speeddriven timing wheel mounted on the output shaft and a second drivingtiming wheel driven by the reversible prime motor through a second beltwith a second low speed driven timing wheel mounted on the second lowspeed input shaft, a reduction gear mechanism contained in said rotarycasing and having a first sun gear integrally formed on said firstdriven timing wheel, a sleeve shaft rotatably mounted on said outputshaft coaxially adjacent to the sun gear and having a second armradially projected therefrom and a second sun gear integrally formedthereon, a first stub shaft so mounted around said output shaft as to berotatable about its own axis and also around said output shaft withinsaid rotary casing in such a manner that the second arm of said sleeveshaft is coupled to the first stub shaft, a second stub shaft so mountedaround said output shaft as to be rotatable about its own axis and alsoaround said output shaft within said rotary casing in such a manner thatthe first arm of said output shaft is coupled to the second stub shaft,first one-way clutch mounted between the first high speed driven timingwheel and the output shaft for coupling only when the first driventiming wheel is rotated in one direction, first and second ring gearsformed on the inner periphery of said rotary casing corresponding to thefirst and second sun gears of said first driven timing wheel and thesleeve shaft, respectively, first and second idle planetary gearsrotatably mounted on the first and second stub shafts, respectively, inmeshing engagement with the first sun and ring gears and second sun andring gears, respectively, a second oneway clutch mounted between theplanetary gear mechanism and the output shaft for disengaging theconnection of the planetary gear mechanism to the output shaft only whenthe first high speed driven timing wheel is coupled with the outputshaft by the one-way clutch, a third one-way clutch mounted between thesecond low speed driven timing wheel and the planetary gear mechanismfor coupling the second low speed driven timing wheel with the planetarygear mechanism only when the second driven timing wheel is rotated inone direction, a torque control mechanism having a non-restrictingelement on the rotary casing, at least one pair of braking elementsmovable relative to each other toward or away from both side surfaces ofsaid non-restricting element.
 8. The driving device according to claim 7further comprising means for alternating slidably the operating positionof said braking elements of said torque control mechanism and having acontrol electric motor, a screw shaft directly coupled to said controlelectric motor and a slider having a nut portion threaded on the screwshaft and so placed as to slide on a stationary base radially of saidbraking elements.
 9. The driving device according to claim 7 whereinsaid braking mechanism is an eddy current braking mechanism whichcomprises a pair of electromagnetic poles disposed on opposite surfacesof the brake element and a control calculator connected to said polesfor controlling the electromagnetic poles.